Application of Atom Probe Tomography for Advancing GaN Based Technology

Atom Probe Tomography (APT) has emerged as a stand-alone technique for material characterization at the sub-nanometer level, with unrivaled spatial resolution, coupled with three-dimensional atomic mapping, and equal sensitivity of all elements. Over the past decade, APT has proven to be a valuable tool in advancing the understanding and design of GaN-based semiconductor technology, by revealing correlations between atomic-level structure chemistry and device performance. The uniqueness of APT is exemplified by its ability to directly analyze nanoscale features within a commercial device. In this review, the quantitative requirements for advancement in GaN-based device metrology are defined as accurate measurement of composition, structural inhomogeneities, elemental incorporation within thin interlayers, and quantification of dopants and impurities. These are bolstered by a review of recent advances in GaN-based devices, realized through APT. The rich compositional and spatial data provided by APT is necessary for the continued advancement of III-V semiconductor technology.